SECTION TWO 



necessary, however, in some cases, to increase the time of exposure 

 to the Millon. 



(h) The reaction of Millon's reagent is due to the hydroxy- 

 phenyl group of the tyrosine. 



(c) Tyrosine, which occurs in most proteins, is the least water- 

 soluble of all the proteins. It is readily soluble in dilute alkalis 

 and mineral acids, but is insoluble in alcohol, acetone, ether and 

 glacial acetic acid. 



(d) The colour produced with Millon's reagent in the above 

 method begins to fade after several hours, although material 

 which is abundant in tyrosine will retain some of the colour for 

 a few weeks. 



References : 

 Bensley, R. R. & Gersh, I. (1933). Anat. Rec, 57, 217-233. 

 Gurr, E. {igs^a), pp. 52-53- 



MUCICARMINE - METANIL YELLOW - 

 HAEMATOXYLIN 



For mucin and connective tissue 



Solutions required: 



A. Haematoxylin (Weigert) A. 



B. Haematoxylin (Weigert) B. 



C. Metanil yellow 0-25% aqueous. 



D. Mucicarmine (Southgate). 



Technique: 



1. Fix material in 10% formalin. 



2. Dehydrate, clear; embed in paraffin wax. 



3. Fix sections to slides; de-wax with xylol and pass through 

 the usual descending grades of alcohol. 



4. Rinse with distilled water. 



5. Stain sections for one minute in a freshly prepared mixture 

 consisting of equal volumes of Solution A and B. 



6. Wash in distilled water. 



7. Immerse in Solution C for about two minutes. 



3" 



